The present invention relates to a connector having a ground pin for boards for providing grounding connection in a circuit board.
There has been provided a connector of this type which is fixed to a board by tacking the connector to the board by way of a ground pin of the connector inserted in a mounting hole of the board, and then soldering a distal end of the ground pin to a back side of the board (see, for example, Japanese Unexamined Utility Model Publication No.1(1989)-63082).
In this connector, however, the ground pin is screw-held to a metallic shell and therefore, an increased number of assembly steps and increased production costs result. The distal end of the ground pin comprises a nib-like claw, which is only capable of engaging a part of an inner periphery of the mounting hole when inserted therein. Therefore, the connector is tacked to the board in such an unstable manner that the connector may be dislocated relative to the board. If the dislocated connector is soldered to the board, the soldered portion is prone to receive an excessive force during the use of the connector. This leads to a problem of the durability of the fixed portion. Furthermore, a positive fixing cannot be ensured because a solder build-up can be formed only on opposite side edges of the claw.
There is provided an alternative connector arranged such that the ground pin formed integrally with the shell has a semi-circular section and that the ground pin is soldered to the boards substantially along a semi-circumference of the mounting hole (see, for example, Japanese Unexamined Patent Publication No.9(1997)-35782). In this case, the fixing strength at which the connector is soldered to the board is somewhat increased but not to a sufficient degree.
By the way, the connector of this type includes a locked member having a snag portion adapted to be locked to an engagement portion of a counterpart connector when this connector is coupled to the counterpart connector in paired relation.
When the counterpart connector is pulled out, the locked member is subject to such a great load that the locked member may sometimes be bent. Therefore, a high strength is required of the locked member.
In this connection, there is provided a connector wherein the locked member is formed integrally with the connector body by die-casting (see, for example, Japanese Unexamined Patent Publication No.7(1995)-335333). However, this method involves high production costs. Furthermore, a screw is used for fixing the connector to the board and hence, the increased number of assembly steps results in increased production costs.
On the other hand, there is provided a connector wherein the ground pin is formed integrally with the locked member by sheet metal (see, for example, Japanese Unexamined Utility Model Publication No.2(1990)-12175). In the case of the one-piece construction, however, the following disadvantages exist although the production costs can be reduced. Specifically, the locked member is required of high rigidity such as to withstand the pulling load from the counterpart connector while on the other hand, the ground pin is required of high resilience in the light of mountability to the mounting hole. Hence, in the case of the one-piece construction, it is quite difficult to satisfy the both requirements of the high strength of the locked member and the mountability of the ground pin. Furthermore, this connector is arranged such that the locked member, snag portion and ground pin are substantially aligned on one straight line. This leads to a fear that the pulling load applied to the snag portion directly acts on the ground pin, resulting in the breakage of the solder around the ground pin.
In view of the foregoing, the present invention has been accomplished. An object of the invention is to provide a connector with ground pin for boards which assumes a stable position when tacked to the boards and is capable of being readily and rigidly fixed to the board.
For achieving the above object, a preferred mode of the invention comprises an insulative connector body accommodating a plurality of contacts; an electromagnetic shielding shell partially covering a surface of the connector body; and a ground pin fixed to the connector body as having electrical conductivity with the shell, wherein the ground pin includes a cylindrical lock portion resiliently deformable in radial direction so as to be inserted through and locked to a mounting hole of a circuit board, and wherein the lock portion resiliently engages the mounting hole substantially on its overall circumference when inserted through the mounting hole.
In this embodiment, the ground pin is tacked to the board by way of the resilient engagement between the lock portion inserted in the mounting hole of the board and the mounting hole. At this time, the tacked connector is less liable to totter because the connector engages an almost entire periphery of the mounting hole. Particularly where the board in an inclined position is subject to a soldering process, the connector can be tacked thereto in a stable manner. Furthermore, the ground pin can be positively fixed to the board because a solder build-up can be formed substantially along the overall periphery of the cylindrical lock portion inserted in the mounting hole of the board.